Geometric morphometrics simplified

Although the theory andmethods of the relatively new field of geometric morphometrics are becoming well developed (for an overview, see [1]), it has not yet been applied as widely as it could be, owing to the lack of easily accessible introductory guides. This primer, by Miriam Zelditch and colleagues, should make the field more accessible because the new methods described here are relatively simple to apply using currently available software. Geometric Morphometrics for Biologists contains chapters that cover most of the basic topics that a potential user needs to know to collect data in an appropriate format and to use standard multivariate methods for the analysis and interpretation of shape variation. The authors provide simple step-by-step (‘click by click’) tutorials on the use of morphometric software, starting with the use of the tpsDig software [2] to collect 2D landmark coordinate data and then discussing the use of the many programs in the IMP series [3] to carry out various analyses. In addition to specialized morphometric methods, the authors also discuss significance testing, resampling methods and other basic statistical methods (however, there are problems with their descriptions of confidence intervals and their relationships to tests of significance). The book also includes chapters about disparity and variation, ontogeny and phylogeny, and morphometrics and systematics. These include some detailed examples and suggestions of new methods (not all of which I agree with). There are exercises with answers at the end of most chapters and a glossary of concepts and terms. A limitation of the book is that methods for 3D data and the use of semi-landmarks along curves and surfaces are relegated to the last chapter. Although the acquisition of 3D coordinate data is more difficult that for 2D data and can require more-expensive equipment, it is now becoming standard in fields such as physical anthropology and primatology and is likely to become more common in the future. Unfortunately, the book is uneven in its presentation. Some concepts are described in such a way that little mathematical background is required, whereas others assume more sophisticated knowledge. For example,